Hydrodynamic noise study of a nonpiezoelectric acoustic decoy

With the increasing intensity of underwater acoustic countermeasures, it is necessary to study a new type of acoustic decoy. It can handle some extreme situations and solve the problem of limited frequency range. In this paper, we present a hypothesis of a non-piezoelectric acoustic decoy for autonomous vocalization by adjusting the rotation and oscillation frequencies. Firstly, his effectiveness is theoretically verified by calculations. Secondly its vortex and acoustic fields are explored. Finally, the sensitivity, which is connecting some parameters and the acoustic field of this decoy, is also analyzed. This acoustic decoy abandons the transducer and adopts a mechanical structure, improving its stability in special environments. In addition, by adjusting the blade swing frequency, a specific main frequency can be modulated, expanding the frequency range.